This is one of those things that you only need on very specific occasions. I needed to get the element that has the focus on a page. Went to Google and found the answer somewhere deep into a forumthread. So for future reference here goes:

I’m very passionate about the code I write, and with the coming of jQuery I really began to love Javascript. But the Javascript I wrote was more of the procedural kind. I tried to split it up per page or user control but it still felt bad. For pages with a lot of interaction the JavaScript files grew very quickly over a couple hundred LOC. There is the possibility to split these up, but the problem that then arises is that the browser launches a request for each javascript file. And most (older) browsers have a suprising low amount of simultaneous request (I thought it was around 2 or 3, it was certainly below 5). So each file I added to make my application more maintainable resulted in a slower application. Not a good situation to be in.

started reading this book about 6 months ago. After reading it half way through I stopped and start reading a newly purchased book. The reason that I stopped reading was because I was excited and impatient to start reading the new book, it’s a problem I have every time I purchase a new book. After finishing some books I realized that jQuery in Action was still lying around, and because the new project I’m working on depends heavily on jQuery, I decided to pick up the book where I left off and finish it.

I notice that a lot of development effort is going into creating a nice back end. Creating a GUI is a matter of using the designer – better known as system.draggy-droppy – and setting the right colors via the properties panel. But lately a shift has happened which forces developers to learn about CSS.